Preserve input order of window functions when planning window operations

[RishiSajay]

Description

Fixes a bug where initial plans for the exact same query string are non-deterministic when the query includes window functions with different resolved windows over the same window. (Resolved window takes into account partition by, order by, etc)

Additional context and related issues

Window functions with the same window are planned in the same operation (see commit). QueryPlanner::planWindowFunctions takes in a list of windowFunctions and converts it into a map to be processed. However, HashMaps do not guarantee input order, leading to different initial query plans for the same query string.

This PR replaces the default HashMap with a LinkedHashMap to preserve the order of resolved windows (and by extension their associated window functions) when planning window functions, therefore guaranteeing the same initial plan every time the same query is run.

Minimal repro and associated diff of initial query plans from 2 different runs before this PR:

WITH data AS (
    SELECT *
    FROM (VALUES 
        ('A', 1, 100),
        ('A', 2, 200),
        ('A', 1, 150),
        ('B', 1, 300),
        ('B', 2, 100),
        ('B', 1, 200)
    ) AS t(category, subcategory, value)
)
SELECT 
    RANK() OVER (
        PARTITION BY category 
        ORDER BY value DESC
    ) AS rank_by_category,
    RANK() OVER (
        PARTITION BY category, subcategory 
        ORDER BY value DESC
    ) AS rank_by_category_subcategory,
    RANK() OVER (
        PARTITION BY category, subcategory, value
        ORDER BY value DESC
    ) AS rank_by_category_subcategory_value
FROM data;

Release notes

(x) This is not user-visible or is docs only, and no release notes are required.
( ) Release notes are required. Please propose a release note for me.
( ) Release notes are required, with the following suggested text:

## Section
* Fix some things. ({issue}`issuenumber`)

[cla-bot]

Thank you for your pull request and welcome to our community. We could not parse the GitHub identity of the following contributors: Rishi Sajay.
This is most likely caused by a git client misconfiguration; please make sure to:

1. check if your git client is configured with an email to sign commits git config --list | grep email
2. If not, set it up using git config --global user.email [email protected]
3. Make sure that the git commit email is configured in your GitHub account settings, see https://github.com/settings/emails

[Copilot]

Copilot reviewed 1 out of 1 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (1)

core/trino-main/src/main/java/io/trino/sql/planner/QueryPlanner.java:1436

• Changing the groupingBy collector to use a LinkedHashMap is the desired fix to preserve the input order; ensure that subsequent usage of this map leverages the order preservation appropriately.

.collect(Collectors.groupingBy(analysis::getWindow, LinkedHashMap::new, Collectors.toList()));

[kasiafi]

Approved % comments.

[cla-bot]

Thank you for your pull request and welcome to our community. We could not parse the GitHub identity of the following contributors: Rishi Sajay.
This is most likely caused by a git client misconfiguration; please make sure to:

1. check if your git client is configured with an email to sign commits git config --list | grep email
2. If not, set it up using git config --global user.email [email protected]
3. Make sure that the git commit email is configured in your GitHub account settings, see https://github.com/settings/emails

[raunaqmorarka]

nit: static import toUnmodifiableList

[RishiSajay]

Fixed

[raunaqmorarka]

Please fix the indentation

[RishiSajay]

Fixed

[cla-bot]

Thank you for your pull request and welcome to our community. We could not parse the GitHub identity of the following contributors: Rishi Sajay.
This is most likely caused by a git client misconfiguration; please make sure to:

1. check if your git client is configured with an email to sign commits git config --list | grep email
2. If not, set it up using git config --global user.email [email protected]
3. Make sure that the git commit email is configured in your GitHub account settings, see https://github.com/settings/emails

[cla-bot]

Thank you for your pull request and welcome to our community. We could not parse the GitHub identity of the following contributors: Rishi Sajay.
This is most likely caused by a git client misconfiguration; please make sure to:

1. check if your git client is configured with an email to sign commits git config --list | grep email
2. If not, set it up using git config --global user.email [email protected]
3. Make sure that the git commit email is configured in your GitHub account settings, see https://github.com/settings/emails

[raunaqmorarka]

@RishiSajay please submit the CLA as described in https://github.com/trinodb/cla
We need that to start merging PRs from any contributor in Trino

[martint]

@cla-bot check

[cla-bot]

Thank you for your pull request and welcome to our community. We could not parse the GitHub identity of the following contributors: Rishi Sajay.
This is most likely caused by a git client misconfiguration; please make sure to:

1. check if your git client is configured with an email to sign commits git config --list | grep email
2. If not, set it up using git config --global user.email [email protected]
3. Make sure that the git commit email is configured in your GitHub account settings, see https://github.com/settings/emails

[cla-bot]

The cla-bot has been summoned, and re-checked this pull request!

[RishiSajay]

@cla-bot check

[cla-bot]

Thank you for your pull request and welcome to our community. We could not parse the GitHub identity of the following contributors: Rishi Sajay.
This is most likely caused by a git client misconfiguration; please make sure to:

1. check if your git client is configured with an email to sign commits git config --list | grep email
2. If not, set it up using git config --global user.email [email protected]
3. Make sure that the git commit email is configured in your GitHub account settings, see https://github.com/settings/emails

[cla-bot]

The cla-bot has been summoned, and re-checked this pull request!